Safety



I II l/ M 7 0/ k I J c Q Patented Apr. 19,1898.

m .m I k w7///////J W F P. T. ELLITHORPE. SAFETY APPLIANCE FORELEVATORS.

(No Model.)

UNITED STATES PATENT OFFICE.

FREDERICK T. ELLIT HORPE, OF NEWARK, JERSEY.

SAFETY APPLIANCE FOR ELEVATORS.

SPECIFICATION formingpart of Letters Patent N0. 602,437, dated April 19,1898.

Application filed February 8, 1898. Serial No. 669,509. (No model.)

I '0 all w/wnt it may concern:

.Be it known that I, FREDERICK T. ELLI- THORPE, a citizen of the UnitedStates, residing at Newark, in the county of Essex and State of NewJersey, have invented new and useful Improvements in Safety Appliancesfor Elevators, of which the following is a specification. I

My invention relates to elevators, and m ore particularly to air-cushionchambers which are provided at the bottom of elevator shafts or wellswith a view of confining air below and thereby gradually arresting thedescent of a falling car, so as to prevent injury to the same and itsfreight.

Air-cushion chambers such as at present in use have an inwardly-openingvalve for the admission of air to prevent suctional resistance frominterfering with the upward movements of the elevator-car, and they alsohave a tapered vent in their side walls, the purpose of which is topermit the escape of compressed air when the car falls, so that said carwill be brought to a gradual stop and will not be arrested as suddenlyas it would be if no provision were made for the escape of air. Suchair-cushion chambers are thoroughly capable of efiecting a gradual stopof a falling elevator-car provided the'fall is not too great, and theyare therefore well adapted for use at the bottom of elevator shafts orwells in buildings of ordinary heightsay from six to ten stories. Theyare not, however, accurately reliable when placed in the elevator shaftsor wells of buildings of extraordinary hei ght-sa y from fifteen totwenty-five storiesbeca-use in such cases in the event of theelevator-car falling irom the top or from a height adjacent to the topit will gain such a momentum that only a comparatively small volume ofair can escape through the vent in the side wall of the air-cushionchamber. This might result in considerable concussion and cause the carto rebound with great force, and in consequence the shaft or well, thecar, and the passengers or freight on the car might be injured.

My invention has for its general object to provide an air cushionchamber which is thoroughly capable of effecting a gradual stop orarrest of a car falling from any reasonable height; and with this end inview said inve ntion will be fully understood from the followingdescription and claims when taken in conjunction with the annexeddrawings, in which- Figure l is a vertical sectional view of an elevatorshaft or well provided with my improved air-cushion chamber at itsbottom. Fig. 2 is an enlarged detail section illustrating thesupplementary valve-controlled airvent of the air-cushion chamber, andFig. 3 is a detail section taken in thewplane indicated by the line a;a: of Fig. 1.

Referring by letter to said drawings, A designates my improvedair-cushion chamber, which is arranged at the bottom of an elevatorshaft or well B, and C designates an elevator-car, which is constructedin a staunch manner and is designed to be raised and lowered in theshaft B by suitable mechanism.

(Not illustrated.)

The air-cushion chamber A is built in a strong manner of steel, masonry,or other suitable material, so as to be able to withstand the tremendouspressure incident to the fall of a heavy car, and is of a'heightproportionate to the height of shaft B, being extended when necessary upto the second and third or higher floors of a building and beingpreferably provided at each landing with a suitable air-tight orsubstantially air-tight door D, such as shown in Fig. 1. Said chamberAhas an air-inlet opening E, an air-vent F, and a supplementary air-ventG. The opening E is designed to admit air to the chamber, so as toprevent suctional resistance from interfering with the upward movementsof the elevator-car, and it is controlled by an inwardlyopening valve H.(Better shown in Fig. 3.) This valve H is snugly set in a rabbet a inthe chamber-wall and is connected at its upper end in a hinged mannerwith a strip 12, which is beveled, as indicated by 0, so as to serve asa stop in limiting the inward movement of the door. At its lower end andon its outer side the valve is provided with a buffer d, of rubber orother suitable material, which strikes a strip e of similar material inthe rabbet and thereby prevents noise when the valve is forcibly closedby the downward movement ofthe car. Said buffer and strip also preventthe valve from being damaged when forcibly closed andthereby materiallyprolong the usefulness of the same.

The vent F is in the form of a verticallyelongated opening, and it isdesigned and adapted to permit the escape of compressed air when the carfalls, so that said car will be gradually stopped and will not bearrested as suddenly as would be the case were no escape for the airprovided.

If the supplementary vent G were normally open like the vent mitted tofreely escape from chamber A, and in consequence no practical cushionwould be formed below a falling car. From this it follows that somesuitable means must be employed for preventing the escape of air throughvent G, except when the air cannot escape through vent F with sufficientrapidity to prevent a sudden stop of a falling car and the consequentconcussion and rebound of the same. For such purpose I prefer to employthe outwardly-opening valve I, which normally sets in a rabbet f in thechamberwall and is connected at its lower end to said wall in a hingedmanner, as shown. This valve I is provided with an aperture 9 and cup hand is backed by a coiled spring 2, which is interposed between the cuph and a cup 70 and surrounds a bowed rod j, extending loosely throughthe said cups, as shown. The cup 7t has athreaded shank l, which takesinto a threaded socket in a stationary pedestal m and is provided with acheck-nut n. Consequently it will be seen that said cup is may bereadily adjusted to regulate the tension of spring 1' and adjustablyfixed when desired.

I do not confine myself to placing the aircontrolling vent as shown inFig. 2, (on the side.) It may be placed in the bottom of elevator-shaft.

In the event of a car falling from a great height or otherwise gainingsuch a momentum that the air in chamber A cannot escape through vent Fsufficiently fast to prevent a sudden stop of the car the valve I willbe forced open against the resistance of the spring e' by the pressureof air in chamber A and will permit the escape of air, withthe resultthat the descent of the car will be gradually arrested, and it will bepermitted to settle gently in the air-cushion chamber. In virtue of thevalve Iopening outwardly and downwardly the volume of escaping air willbe gradually diminished as the car moves downwardly past vent G. This,as will be readily appreciated, contributes materially to the gradualand etfectual stoppage of the car.

As stated in the foregoing, my'improved air-cushion is designed moreparticularly for use at the bottom of elevator shafts or wells F, theair would be per of extraordinary height. I desire .it understood,however, that it may be employed to advantage at the bottom of shafts orwells of ordinary height, when desired, inasmuch as the valvel remainstightly closed until the vent F fails to permit the air to escape fromthe chamber .with sufficient rapidity to prevent the sudden stop of aheavy or loaded car, when said valve 1 will be opened and will effect agradual stop of the car and prevent damage, as before described.

Having thus described my invention, what I claim is- 1.- The combinationof an elevator-car and a shaft or well, an air-cushion "at its bottomprovided with two air-vents and also provided with suitable means forpreventing the escape of air through one vent until the other vent failsto permit the air to escape with suflieient rapidity to prevent thesudden stop of a falling car, substantially as specified.

2. The combination of an elevator-car, and a shaft or well, anair-cushion at its bottom provided with an inwardly-opening valve forthe admission of air and also provided with an open air-vent and avalve-controlled airvent, substantially as specified.

3. The combination of an elevator-car and a shaft or well, anair-cushion at its bottom provided with two ai r-vents and also providedwith-a downwardly and outwardly movable 'alve controlling oneof-saidvents, substantially as specified.

4. The combination of an elevator-car, a shaft or well, an air-cushionchamber at the bottom of the shaft or well having two airvents, and aspring-backed valve connected at its lower end in a hinged manner to theoutside of one wall of the chamber below one air-vent whereby it isadapted to open outwardly and downwardly, substantially as specified.

5. The combination of an elevatorcar, a shaft or well, an air-cushionchamber at the bottom of the shaft or well having two airvents, a valveconnected at its lower end in a hinged manner to the outside of one wallof the chamber below one air-vent whereby it is adapted to opendownwardly and outwardly. a pedestal, a cup adjustably connected withthe pedestal, a bowed guide-rod resting in the cup and extending looselythrough an aperture in the valve, and a spring surrounding said rod andinterposed between the cup and the valve, substantially as specified. y

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

FREDERICK T. ELLITIIORPE.

\Vitnesses:

I. S. LAWRENCE, FRANK L. BoPPE.

